[Method of determination of the number of enteroviruses present in natural waters].

The effectiveness of concentratin of enteroviruses present in water by adsorption on membrane filters, ion-exchange resin AB-17-8 and bentonite was compared with set concentrations of virus in water (0.05-0.1-0.5-2.5 and 12.5 PFU/ml). The effectiveness of concentration was shown to depend upon the initial dose of virus present in water. With virus adsorption on membrane filters and ionexchange resin the effectiveness of concentration was the higher (100 and 74%) the lower the virus dose in water (0.05 PFU/ml), with bentonite the effectiveness was the higher (60%) the higher virus dose in water (12.5 PFU/ml). A method is proposed for sufficiently accurate determination of virus concentration in water by simultaneous and parallel removal of virus particles in two ways one of which gives a maximum effect with low doses of virus and the other with large doses.